Typically trailers, caravans, boat trailers, horse floats and the like are provided with a jockey or manoeuvring wheel assembly. The wheel assembly is provided to facilitate movement of the trailer over relatively short distances. The wheel assembly typically includes a raising and lowering mechanism for both levelling of the trailer, and the engagement of and/or removal of the towing hitch from the tow-ball.
Manually manoeuvring of the trailer via the jockey wheel is relatively simple when the trailer is carrying a light load. However in instances where the trailer is carrying a large load, manual manoeuvring the trailer can be exceedingly difficult. In such situations the trailer may escape the control of a person manoeuvring the trailer and start to freewheel. This freewheeling can result in the trailer colliding into the towing vehicle, or worse still running down the person manoeuvring the trailer. Accordingly, a number of jockey wheel manufacturers have implemented several arrangements in order to aid manoeuvring and to reduce the risk of freewheeling.
One such arrangement is disclosed in WO 2004037567 entitled ‘Jockey Wheel Assembly’, which describes a jockey wheel assembly having a drive system including a crank coupled to a rotatable shaft which is inturn coupled to the wheel hub. Rotation of the crank causes rotation of the shaft, this rotation then being translated into linear movement by the wheel, in a forward or reverse direction depending on the direction of rotation of the crank. The assembly is also provided with a tiller which enables the user to control the direction the wheel is facing and thus control the direction of movement of the trailer. The problem with such an arrangement is that it utilises a number of gears and these gears under the strain of moving such large loads are prone to wear, sheering and slippage, which can lead to a momentarily loss of control over the trailer. This momentary loss of control may be all that is required to cause the trailer to freewheel.
Another example of such a jockey wheel assembly is disclosed in AU 2002100165 to Ark Engineering Pty Ltd entitled ‘Jockey Wheel’. The assembly includes a frame mountable on a trailer, a wheel frame and a lever arm. The lever includes a ratchet arm which mates with a corresponding pawl mounted on the frame. The pawls being operable upon pivotal movement of the lever to selectively move or restrain rotation of the wheel in the frame. Again such an arrangement utilises a complex mechanical arrangement which is prone wear to shearing and slippage.
Furthermore in both the above arrangements the tyre of the jockey wheel is prone to slip on the wheel hub when the hub is mechanically driven. Such a slippage again can lead to the trailer freewheeling. If the tyre is a pneumatic tyre this slippage can tear out the valve stem leading to deflation of the tyre requiring the replacement of the stem or entire inner tube.
Clearly it would be advantageous to provide an alignment apparatus which substantially ameliorates one or more of the aforementioned problems and that is relatively simple to manufacture and use.